Overlapping antenna arrays for gaming

ABSTRACT

A system and method of locating gaming tokens on a gaming table. Two sets of overlapping antennas are arranged in intersecting directions. The system uses the data from intersecting antennas to determine the positions of the gaming tokens. Having overlapping antennas reduces dead spots.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional App. No.61/904,981 for “Overlapping Antenna Arrays for Gaming” filed Nov. 15,2013.

BACKGROUND

The present invention relates to gaming, and in particular, to locatinggaming chips on a gaming table.

Unless otherwise indicated herein, the approaches described in thissection are not prior art to the claims in this application and are notadmitted to be prior art by inclusion in this section.

In a casino gaming environment, there is a need for efficiency, accuracyand auditing. Efficiency relates to the speed of the game, whichcontributes to player engagement as well as increases the rate of returnon the game. Accuracy relates to the correctness of intakes and payouts,which contributes to player satisfaction as well as conforms the rate ofreturn to historical expectations. Auditing relates to the ability ofmanagement to review the efficiency and accuracy.

Traditionally, casinos have relied on training to meet their goals forefficiency, accuracy and auditing. Well-trained dealers are moreefficient and accurate. Well-trained pit bosses are more easily able toview, review and audit the activities of the dealers and players.

More recently, radio frequency identification (RFID) technology is beingdeployed in casinos. Gaming tokens include RFID tags, and gaming tablesinclude RFID readers. The particular location of a gaming token on agaming table is often important; however, this is a challenge for RFIDtechnology. One solution is to define specific betting spots on a gamingtable, associate an RFID antenna with each betting spot, and thenengineer the system such that each RFID antenna only detects the RFIDtokens located in its betting spot. Various techniques may be used toengineer the system; these include providing physical space betweenadjacent betting spots, providing electromagnetic shielding (e.g.,ground loops) around antennas, generating cancellation fields, etc.

FIG. 1 is a top view of a stylized Baccarat table 100. The table 100includes 12 seated player positions, each having a player betting spot(individually numbered 120 a-120 l) and a dealer betting spot(individually numbered 130 a-130 l). Within a betting spot (e.g., 120 aor 130 a), the seated player may place one or more gaming tokens (abet), and one or more bettors may each place one or more gaming tokens(additional “back bets”). The table also includes betting spots 140 aand 140 b for placing bets on a tie. Generally, each bet associated withan entity (either the seated player or the back bettor) is placed as adiscrete stack for easy identification by the gaming personnel. Thus, abetting spot may have multiple stacks of gaming tokens (with a singlegaming token being considered a “stack” for purposes of thisdiscussion).

FIG. 2 is a top view of a stylized roulette table 200. The table 200includes a wheel (not shown) and numerous betting spots (shown as boxesin the grid 220). A betting spot indicates a specific number (e.g., 1,2, 3, etc.) or various groupings (e.g., red, black, odd, even, etc.)that the wheel may indicate. For a particular betting spot (e.g., 220a), a bet may be placed within the betting spot (a “straight” bet,indicating a bet only on that spot), on the line between two spots (a“split” bet, indicating the bet is on both of those two spots), or atthe intersection of two lines (a “corner” bet, indicating the bet is onall four of the spots surrounding the intersection). Other types of betsmay be indicated by other placements of gaming tokens, such as a“street” bet (three numbers in a line), a “line” or “double street” bet(two adjacent lines each having three numbers), a “top line” (fivenumber) bet (0, 00, 1, 2, 3), etc. The game has multiple players, andeach player may place multiple bets. For ease of identification,roulette players use gaming tokens having different colors. Thus, abetting spot (or intersection between spots) may have one or more stacksof gaming tokens, each stack having one or more colors.

SUMMARY

As RFID systems have been deployed in gaming environments, variousissues have been observed. One issue is that some gaming tables (e.g.,roulette) have discrete betting areas that are close together. Onesolution would be to use closely-spaced antennas to read theclosely-spaced betting areas. However, there is a limit to how closelythe antennas may be spaced, in order for a particular antenna not todetect the tokens in an adjacent betting spot. This results in various“blind spots” on the gaming table in which tokens may not be detected.

Another issue is that some gaming tables have a betting area in whichmultiple players may place gaming tokens. For example, a Baccarat handoccurs between a “banker” and a “player”, with seated players able toplace bets on the banker, the player, or a tie. Non-seated players(“back bettors”) may also place bets for the player, the banker or a tieusing the same betting spots; thus, gaming tokens may be placed at manypotential locations on a table. One solution to tracking these betswould be to subdivide the “player”, “banker”, and “tie” betting spotsinto defined subspots each having its own antenna. However, on a typicaltable layout, these subspots will still have spacing and blind spotissues. In addition, the need to place bets within defined subspots maydetract from player enjoyment by requiring tokens to be placed moreprecisely as compared to a traditional gaming table layout withoutdefined subspots.

In response to the above-noted shortcomings, an embodiment provides anarray of overlapping, intersecting antennas in a betting spot. Thespecific location of a gaming token within the betting spot may bedetermined by the intersection of two or more antennas. Since theantennas are overlapping, there are no blind spots. The intersectingantennas allow gaming tokens to be identified at multiple locationswithin the betting spot (including identifying multiple gaming tokens ina stack at a single location as a single, discrete bet). In this manner,the system is able to detect that there are multiple, discrete groupingsof tokens (each at a different location) within a betting spot, as wouldbe the case when multiple players place bets there. The ability todefine the location of individual bets is also helpful when it comestime to collect losing bets and payout winning bets. To accuratelyassociate a specific payout with a specific winning bet is useful andknowing the spatial coordinates of winning bets is part of a workingsolution. In addition, the system increases the efficiency, accuracy andauditing of the gaming environment by providing automated tracking,counting and recordkeeping to augment the gaming personnel.

According to an embodiment, a system locates gaming tokens on a gamingtable. The system includes a first set of antennas oriented in a firstdirection, a second set of antennas oriented in a second direction thatdiffers from the first direction, and a control circuit coupled to thefirst and second sets. The first set of antennas defines a betting areaof the gaming table. The first set includes a first subset of antennasand a second subset of antennas. The first subset and the second subsetare overlapping, as well as the first set and the second set areoverlapping. The second set includes a third subset of antennas and afourth subset of antennas. The third subset and the fourth subset areoverlapping. The control circuit is configured to selectively energizethe first and second sets, is configured to receive a first plurality ofsignal strengths resulting from reading an RFID gaming token in thebetting area according to the first set being selectively energized, andis configured to receive a second plurality of signal strengthsresulting from reading the RFID gaming token in the betting areaaccording to the second set being selectively energized. The controlcircuit is configured to determine a location of the RFID gaming tokenin the betting area by comparing the first plurality of signal strengthsand the second plurality of signal strengths.

According to an embodiment, a system locates gaming tokens on a gamingtable. The system includes a first set of antennas oriented in a firstdirection, and a control circuit coupled to the first set. The first setof antennas defines a betting area of the gaming table. The first setincludes a first subset of antennas and a second subset of antennas. Thefirst subset and the second subset are overlapping. The control circuitis configured to selectively energize the first and second subsets, isconfigured to receive a first signal strength resulting from reading anRFID gaming token in the betting area according to the first subsetbeing selectively energized, and is configured to receive a secondsignal strength resulting from reading the RFID gaming token in thebetting area according to the second subset being selectively energized.The control circuit is configured to determine a location of the RFIDgaming token in the betting area by interpolating between the firstsignal strength and the second signal strength.

According to an embodiment, a system locates gaming tokens on a gamingtable. The system includes a first set of antennas oriented in a firstdirection, a second set of antennas oriented in a second direction thatdiffers from the first direction, and a control circuit coupled to thefirst and second sets. The first set of antennas defines a betting areaof the gaming table. The first set includes a first subset of antennasand a second subset of antennas. The first subset and the second subsetare overlapping, as well as the first set and the second set areoverlapping. The control circuit is configured to selectively energizethe first and second sets, to receive a first plurality of signalstrengths resulting from reading an RFID gaming token in the bettingarea according to the first set being selectively energized, and isconfigured to receive a second plurality of signal strengths resultingfrom reading the RFID gaming token in the betting area according to thesecond set being selectively energized. The control circuit isconfigured to determine a location of the RFID gaming token in thebetting area by comparing the first plurality of signal strengths andthe second plurality of signal strengths.

According to an embodiment, a method may locate gaming tokens on agaming table. The method may be executed by a computer system thatcontrols the energizing of the antennas and the determination of thelocation of the RFID gaming token, in a manner similar to that describedabove.

An embodiment is noteworthy because it easily accommodates back bettors.The primary argument to accommodating back bettors is simple: casinoincome is based on statistics and volume. Back bettors increase thevolume of bets on a given game. However, back bettors contribute to acertain amount of chaos. The technology described in this document isdesigned to help manage that chaos.

The following detailed description and accompanying drawings provide afurther understanding of the nature and advantages of embodiments of thepresent invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of a stylized Baccarat table.

FIG. 2 is a top view of a stylized roulette table.

FIG. 3 is a top view of overlapping antennas that are oriented in onedirection (e.g., east-west as shown).

FIG. 4 is a top view of overlapping antennas that are oriented inanother direction (e.g., north-south as shown) that differs from thedirection of the antennas of FIG. 3.

FIG. 5 is a cross-sectional view of a stylized electromagnetic fieldgenerated by the antennas of FIG. 3.

FIG. 6 is a cross sectional view of stylized electromagnetic fields.

FIG. 7 is a top view of intersecting, overlapping antennas.

FIG. 8 is a top view showing the detectable locations of theintersecting, overlapping antennas of FIG. 7.

FIG. 9 is a top view of a betting area.

FIG. 10 is a block diagram of a system for controlling an antenna arraysuch as the intersecting, overlapping antennas of FIG. 7.

FIG. 11 is a flowchart of a method of locating gaming tokens on a gamingtable.

FIG. 12A is a cross-sectional view of a stylized electromagnetic fieldgenerated by the antennas of FIG. 3.

FIG. 12B is a cross-sectional view of the stylized subfields that makeup a portion of the field of FIG. 12A.

FIG. 13 is a stylized top view of a portion of the Baccarat table ofFIG. 1, with the addition of overlapping, intersecting antennas.

FIG. 14 is a stylized top view of the roulette table of FIG. 2, with theaddition of overlapping, intersecting antennas.

FIG. 15 is a diagram showing a system and antenna array where theantennas are overlapping and oriented in a single direction.

FIG. 16 is a diagram showing a system and antenna array where theantennas in one direction are overlapping, and the antennas in anotherdirection are not overlapping.

DETAILED DESCRIPTION

Described herein are techniques for locating gaming tokens. In thefollowing description, for purposes of explanation, numerous examplesand specific details are set forth in order to provide a thoroughunderstanding of the present invention. It will be evident, however, toone skilled in the art that the present invention as defined by theclaims may include some or all of the features in these examples aloneor in combination with other features described below, and may furtherinclude modifications and equivalents of the features and conceptsdescribed herein.

In the following description, various methods, processes and proceduresare detailed. Although particular steps may be described in a certainorder, such order is mainly for convenience and clarity. A particularstep may be repeated more than once, may occur before or after othersteps (even if those steps are otherwise described in another order),and may occur in parallel with other steps. A second step is required tofollow a first step only when the first step must be completed beforethe second step is begun. Such a situation will be specifically pointedout when not clear from the context.

In this document, the terms “and”, “or” and “and/or” are used. Suchterms are to be read as having an inclusive meaning. For example, “A andB” may mean at least the following: “both A and B”, “at least both A andB”. As another example, “A or B” may mean at least the following: “atleast A”, “at least B”, “both A and B”, “at least both A and B”. Asanother example, “A and/or B” may mean at least the following: “A andB”, “A or B”. When an exclusive-or is intended, such will bespecifically noted (e.g., “either A or B”, “at most one of A and B”).

As discussed above, FIG. 1 is a top view of a stylized Baccarat table100. As further detailed below, the table 100 includes overlapping,intersecting antennas in each betting spot to determine the discretelocation of each bet.

As discussed above, FIG. 2 is a top view of a stylized roulette table200. As further detailed below, the table 200 includes overlapping,intersecting antennas under the grid 220 to determine the discretelocation of each bet.

Besides roulette there are other casino games that allow back bettorsand other multi-player bets in a betting area. These games include manyof the table games such as 3-card poker, blackjack, Pai Gow poker,double-hand poker, etc.

FIG. 3 is a top view of overlapping antennas 300 that are oriented inone direction (e.g., east-west as shown). The antennas 300 are generallyrectangular with rounded ends. The antennas 300 are arranged as a topset 310 (individually 310 a-310 e) and a bottom set 320 (individually320 a-320 d). The top set 310 overlaps the bottom set 320, whicheliminates dead spots (as discussed below). The distance “d” denotes thedistance between centerlines of adjacent antennas. According to anembodiment, “d” is 1.78 inches. The number, size and shape of theantennas 300 may vary based on design requirements, as further discussedbelow. The sets 310 and 320 may be formed on a multi-layer printedcircuit board. Alternatively, each set may be formed on its own circuitboard, and the circuit boards for the sets 310 and 320 are placed oneatop the other underneath the betting spot (or larger betting area suchas the grid 220 of FIG. 2) on the gaming table. The spacing of theoverlapping antennas can be tailored to the spatial accuracy needed toidentify the location of specific bets. For large or irregularly-shapedbetting areas, multiple circuit boards or circuit boards with differentsizes and shapes may be used.

FIG. 4 is a top view of overlapping antennas 400 that are oriented inanother direction (e.g., north-south as shown) that differs from thedirection of the antennas 300 (see FIG. 3). The antennas 400 arearranged as a top set 410 (individually 410 a-410 e) and a bottom set420 (individually 420 a-420 d). The top set 410 overlaps the bottom set420, which eliminates dead spots. The distance “d” denotes the distancebetween centerlines of adjacent antennas. The antennas 400 are otherwisesimilar to the antennas 300 (see FIG. 3).

FIG. 5 is a cross-sectional view of a stylized electromagnetic field 500generated by the antennas 300 (see FIG. 3). The line of the field 500 isdrawn to show the nominal detection range above the antennas 300. Thefield 500 is generally continuous above the antennas 300 and has no deadspots.

A similar field exists regarding the antennas 400 (see FIG. 4).

FIG. 6 is a cross sectional view of stylized electromagnetic fields 600.The fields 600 are generated by antennas that are not overlapping, suchas if the top set 310 (see FIG. 3) were present without the bottom set320. The lines of the fields 600 are drawn to show the nominal detectionrange of each of the antennas 310. Dead spots 610 between the fields 600result from lacking overlapping antennas. Thus, to avoid dead spots(e.g., as in FIG. 5), it is desired to use overlapping antennas (e.g.,the antennas 300 of FIG. 3) instead of non-overlapping antennas.

A similar field would exist if the bottom set 420 (see FIG. 4) werepresent without the top set 410.

FIG. 7 is a top view of intersecting, overlapping antennas 700. Forexample, the intersecting, overlapping antennas 700 may be formed byoverlapping the east-west antennas 300 (see FIG. 3) and the north-southantennas 400 (see FIG. 4). Each area of intersection between one antennafrom 300 and one antenna from 400 defines a discrete location in whichgaming tokens may be detected, as shown in FIG. 8. The antennas 700(sets 310 and 320 in FIG. 3, sets 410 and 420 in FIG. 4) may be formedon a multi-layer printed circuit board. Alternatively, the sets may beformed on more than one circuit board that are overlapped (e.g., 310 and320 on one circuit board, overlapping 410 and 420 on another circuitboard). The intersecting, overlapping antennas may also be referred toas an array (e.g., the array 700).

FIG. 8 is a top view showing the detectable locations 800 of theintersecting, overlapping antennas 700 (see FIG. 7). Each of thelocations 800 occurs above the intersection of one of the east-westantennas 300 (see FIG. 7) and one of the north-south antennas 400 (seeFIG. 7). For illustrative purposes, the locations above intersectingantennas that are both shown as solid in FIG. 7 are shown with solidlines in FIG. 8 (20 locations); the locations above all the otherintersections (solid and dotted, or both dotted) are shown with dottedlines (43 locations). Since the antennas 300 and 400 (see FIG. 7) areoverlapping, the locations 800 cover the entirety of the betting area,resulting in no dead spots.

As an example, gaming tokens are discriminated at the location 800 a bydetecting the tokens using the antenna 300 a and the antenna 400 a (seeFIG. 7). First, the system energizes one of the antennas 300 (e.g., 300a). This results in detecting the tokens in the field above the antenna300 a. However, note that their specific location is not yet known; atthis time the only information is that the tokens may be anywhere withinthe detection field of the antenna 300 a. In other words, this firstdata set determines only one of the two coordinates used to locate apoint in a plane. Next, the system energizes one of the antennas 400(e.g., 400 a) to determine the second coordinate. This results indetecting the tokens in the field above the antenna 400 a. Since theantennas 300 a and 400 a intersect, the location of the tokens isdetermined to be the location 800 a that corresponds to the intersectionarea.

FIG. 9 is a top view of a betting area 900. The betting area 900includes a number of gaming tokens (or stacks of gaming tokens) 902, 904and 906. The distance “D” denotes the distance between centers ofadjacent stacks. Thus, for a system with the distance “d” of FIG. 3 andFIG. 4, the system is able to detect multiple stacks of tokens asseparate and distinct stacks as long and they are separated by thedistance “D” that is greater than “d”. So given the token diameter, thedistance “d” of the antennas may be adjusted in order to provide thedesired level of discrimination among the potential locations.

FIG. 10 is a block diagram of a system 1000 for controlling an antennaarray such as the intersecting, overlapping antennas 700 (see FIG. 7).The system 1000 includes a controller 1010 and subcontrollers 1020,1022, 1024 and 1026. The system 1000 may connect to a computer 1030 thatexecutes a control program for controlling the system 1000. Theconnection may be via a universal serial bus (USB) connection. Thecomputer 1030 may connect to a central control computer 1040 thatstores, for example, a chip database. The connection may be via a localarea network (e.g., Ethernet).

The controller 1010 provides power to the subcontrollers 1020, 1022,1024 and 1026. The controller 1010 coordinates the operation of thesubcontrollers 1020, 1022, 1024 and 1026, by selectively instructing thesubcontrollers to activate, receiving token identification data(including signal strength information) from the subcontrollers, andsending the token identification data to the computer.

The subcontrollers 1020, 1022, 1024 and 1026 respectively connect to theantenna sets 300 and 400 (see FIG. 7; includes the sets 310 and 320 inFIG. 3 and the sets 410 and 420 in FIG. 4). A subcontroller (e.g., 1020)selectively energizes the antennas in the corresponding antenna set(e.g., 310), receives the token identification data from thecorresponding antenna set, and sends the token identification data tothe controller 1010.

The computer 1030 may instruct the system 1000 to operate according to avariety of detection options, as more fully discussed below. Thecomputer 1030 may control multiple systems 1000, for example asimplemented on a single gaming table or on multiple gaming tables. Thecomputer may be one of multiple computers (e.g., each controlling one ormore system 1000) that connect to the central control computer 1040.

FIG. 11 is a flowchart of a method 1100 of locating gaming tokens on agaming table. The method may be performed by the system 1000 (see FIG.10) or the computer that controls the system 1000, for example ascontrolled by a computer program.

At 1102, a first set of antennas oriented in a first direction areprovided. For example, the antennas 300 (see FIG. 3) may be provided.The first set of antennas defines a betting area of the gaming table.The first set includes a first subset of antennas and a second subset ofantennas, where the first subset and the second subset are overlapping.For example, the antennas 300 (see FIG. 3) include a set 310 and a set320 that overlap.

At 1104, a second set of antennas oriented in a second direction areprovided. The second direction differs from the first direction. Forexample, the antennas 400 (see FIG. 4) are oriented in a north-southdirection, which differs from the east-west orientation of the antennas300 (see FIG. 3). The first set and the second set are overlapping. Forexample, the antennas 300 and the antennas 400 (see FIG. 7) areoverlapping. The second set includes a third subset of antennas and afourth subset of antennas, where the third subset and the fourth subsetare overlapping. For example, the antennas 400 (see FIG. 4) include aset 410 and a set 420 that overlap.

At 1106, the first and second sets are selectively energized. Forexample, the controller 1010 (see FIG. 10) may instruct thesubcontrollers 1020, 1022, 1024 and 1026 to selectively energize theantennas 300 and 400. Further details on the various ways in which theantennas may be selectively energized are provided below.

At 1108, a first plurality of signal strengths is received, resultingfrom reading a radio frequency identification (RFID) gaming token in thebetting area according to the first set being selectively energized. Forexample, the controller 1010 may receive the token identification datafrom the subcontrollers 1020 and 1022, resulting from reading the gamingtokens detected by the antennas 300. The signal strengths may also bereceived as binary data, e.g., one symbol (e.g., the value 1) when anantenna detects the token, and another symbol (e.g., the value 0) whenan antenna does not detect the token.

At 1110, a second plurality of signal strengths is received, resultingfrom reading the RFID gaming token in the betting area according to thesecond set being selectively energized. For example, the controller 1010may receive the token identification data from the subcontrollers 1024and 1026, resulting from reading the gaming tokens detected by theantennas 400.

At 1112, a location of the RFID gaming token in the betting area isdetermined by comparing the first plurality of signal strengths and thesecond plurality of signal strengths. For example, the computer (seeFIG. 10) may select the highest signal strength detected by the antennas300 (which is associated with the antenna 310 a), may select the highestsignal strength detected by the antennas 400 (which is associated withthe antenna 410 a), and may determine that the gaming token is locatedin the area defined by the intersection of the antenna 310 a and theantenna 410 a. When the signal strengths are binary data as discussedabove, the intersection of the two antennas that return the value 1corresponds to the location of the gaming token. When the signalstrengths are within the range of a maximum signal strength and aminimum signal strength, the location of the gaming token may bedetermined using interpolation, as described below.

Additional Details and Design Options

The following sections discuss additional details and design options.

Token Detection Options

With the overlapping, intersecting antennas, a gaming token in thebetting area will be detected by at least two intersecting antennas(e.g., detected by 310 a and 410 a in FIG. 7, indicating location 800 ain FIG. 8). However, since the antennas oriented in a particulardirection (e.g., the antennas 300 in FIG. 3) are overlapping, there isthe possibility that more than one of these antennas will detect thetoken, albeit with differing signal strengths due to the differentdistances between the token and the antennas. (If a particular antennafails to detect the token, the system may assign a signal strengthmeasurement of zero to that antenna.) The system may implement a numberof ways in which to correlate the received signal strengths and thepositions on the gaming table.

One way is to use the highest signal strength detected. For example,energizing the antennas results in the signal strength measurements ofTABLE 1:

TABLE 1 Antenna Signal Strength 310a 1.0 320a 0.5 310b-310e, 320b-320d 0410a 1.0 420a 0.5 410b-410d, 420b-420c 0

Of the antennas in the set 300, the antenna 310 a has the highest signalstrength; similarly antenna 410 a of the set 400. Thus, the systemdetermines that the token is located at the intersection of the antennas310 a and 410 a.

Another way is to interpolate between the various signal strengths. Forexample, energizing the antennas results in the signal strengthmeasurements of TABLE 2:

TABLE 2 Antenna Signal Strength 310a 0.5 320a 0.5 310b-310e, 320b-320d 0410a 0.5 420a 0.5 410b-410d, 420b-420c 0

To determine the location, the system determines the position byinterpolating among the signal strengths of each set. For the set 300,the total signal strength is 1.0 (0.5+0.5); the total is half associatedwith the antenna 310 a (0.5/1.0) and half associated with the antenna320 a (0.5/1.0), so the north-south position is interpolated as halfwaybetween 310 a and 320 a. For the set 400, the total signal strength is1.0 (0.5+0.5); the total is half associated with the antenna 410 a(0.5/1.0) and half associated with the antenna 420 a (0.5/1.0), so theeast-west position is interpolated as halfway between 410 a and 420 a.The overall position is then the intersection of the north-southposition and the east-west position.

Multiple Location Detection Options

As mentioned above, the system is able to determine the positions ofmultiple bets within the betting spot, to determine that a stack oftokens in a single location are associated as a single bet, and todetermine that multiple stacks correspond to multiple bets at multiplepositions within the betting spot. In general, a stack may be around 20tokens high (a convenient height to manipulate with one hand), so thepower supplied to the antennas may be adjusted to sufficiently read thatdistance. Alternatively, the power supplied may start at a minimal leveland then ramp up in order to read tokens at successively greaterdistances. As discussed below, each token has an identifier that is readwhen the antenna detects the token, allowing for signal strengthmeasurements to be associated with each token.

When there are multiple single tokens each at a different location, thesystem detects the position of each as it selectively energizes theantennas. For example, when the antenna 310 a (see FIG. 3) is energized,it detects two tokens with identifiers ID0001 and ID0002, both havingsignal strengths 1.0. When the antenna 410 a (see FIG. 4) is energized,it detects token ID0001 with signal strength 1.0, and when the antenna410 b is energized, it detects token ID0002 with signal strength 1.0.(Assume the remaining antennas do not detect any tokens.) Thus, theposition of token ID0001 is determined as the intersection of antennas310 a and 410 a, and the position of token ID0002 is determined as theintersection of antennas 310 a and 410 b.

When there are multiple tokens in a single stack, the system detects theposition of each as it selectively energizes the antennas. For example,when the antenna 310 a (see FIG. 3) is energized, it detects two tokenswith identifiers ID0001 and ID0002, both having signal strengths 1.0.When the antenna 410 a (see FIG. 4) is energized, it detects tokensID0001 and ID0002, both having signal strengths 1.0. (Assume theremaining antennas do not detect any tokens.) Thus, tokens ID0001 andID0002 are determined to be a stack, with the position of the stackdetermined as the intersection of antennas 310 a and 410 a.

When there are multiple stacks or a combination of one or more stacksand one or more single tokens, the system detects the position of eachas it selectively energizes the antennas. For example, when the antenna310 a (see FIG. 3) is energized, it detects two tokens with identifiersID0001 and ID0002, both having signal strengths 1.0. When the antenna310 b is energized, it detects token ID0003 with signal strength 1.0.When the antenna 410 a is energized, it detects all three tokens ID0001,ID0002 and ID0003 with signal strength 1.0 each. (Assume the remainingantennas do not detect any tokens.) Thus, tokens ID0001 and ID0002 aredetermined to be a stack at the position of the intersection of antennas310 a and 410 a, and the token ID0003 is determined at the position ofthe intersection of antennas 310 b and 410 a.

Minimum Threshold Signal

The system may be configured to recognize a minimum threshold signal.For example, if the signal strength of 0.5 results when tokens arehalfway above the antenna, a minimum threshold signal level of 0.1 maybe set. The system ignores signal strength measurements below theminimum, as those measurements may result from a particular antennareading tokens that are more strongly read by another antenna. Thishelps the system to use enough antenna power to detect a token at thetop of the stack, yet ignore a token at the bottom of an adjacent stack.

Interpolation Options

FIG. 12A is a cross-sectional view of a stylized electromagnetic field1200 generated by the antennas 300 (see FIG. 3). The field 1200 issimilar to the field 500 (see FIG. 5), except the field 1200 is shown abit less stylized: the field 1200 is strongest above the center of eachof the antennas 300, and decreases toward the edge of each antenna. As aresult, the strength of the field 1200 has a wave or ripple shape asshown.

FIG. 12B is a cross-sectional view of the stylized subfields that makeup a portion of the field 1200 (see also FIG. 12A). The subfield 1202 isgenerated by the antenna 310 a (see FIG. 3), the subfield 1204 isgenerated by the antenna 320 a, and the subfield 1206 is generated bythe antenna 310 b. (When combined, the subfields 1202, 1204 and 1206result in a portion of the field 1200, with its ripple shape).

FIG. 12B illustrates more details concerning how the location of tokensmay be interpolated. Consider tokens ID0001, ID0002 and ID0003 placed atrespective locations 1212, 1214 and 1216. The antennas detect thesetokens with the strengths listed in TABLE 3 (where tokens not detected,or detected at strengths below a set threshold, are considered to bezero and not listed):

TABLE 3 Token Identifier Antenna Strength ID0001 310a 1.0 ID0001 320a0.1 ID0002 310a 0.8 ID0002 320a 0.8 ID0003 320a 0.95 ID0003 310a 0.2ID0003 310b 0.05

A variety of processes may be implemented to translate the signalstrength information into location information. One example is to use alinear ratio, applied to TABLE 3 as follows. For token ID0001, thehighest signal strength corresponds to antenna 310 a, so the startingposition is the center of antenna 310 a. The signal for the token ID0001is also detected by antenna 320 a, so the position of the token isoffset by a ratio0.1/(1.0+0.1)=0.091=9.1%

That is, the ultimate position is determined by an offset of 9.1% fromthe center of the antenna 310 a toward the center of the antenna 320 a.The offset may also be referred to as the fractional distance.

For token ID00002, the offset is0.8/(0.8+0.8)=0.5=50%

That is, the position of ID0002 is offset 50% from the center of theantenna 310 a toward the center of the antenna 320 a.

For token ID0003, the offset is0.2/(0.95+0.2)=0.174=17.4%

That is, the position of ID0003 is offset 17.4% from the center of theantenna 320 a toward the center of the antenna 310 a. Note that thelowest signal strength measurement of 0.05 may be discarded.

The interpolation may be implemented by the system 1000 (see FIG. 10) aspart of energizing the antennas and receiving the signal strengthmeasurements. The controller 1010 may perform the interpolation, or thecomputer 1030 may perform the interpolation.

Antenna Arrangement Options

The size, shape and arrangement of the overlapping, intersectingantennas (e.g., FIG. 7) may be adjusted as desired. In general, the gametype, table size and size of betting areas will be the primary designfactors. Additional design factors include variations on the game type,local laws, casino rules, casino branding and graphics, etc.

The antenna array of FIG. 7 may be combined with other antennas that arenot overlapping. The non-overlapping antennas may be used to read tokensin a specific, designated area.

Another way to determine the position of tokens is to use polarcoordinates instead of the x-y grid of FIG. 7. To measure the distancefrom a center point, a first set of antennas are each arranged inoverlapping, concentric rings. A second set of antennas is overlappingwith the first set, and is arranged in another configuration thatcreates intersections between the two sets. For example, therectangular, rounded antennas of FIG. 3 or FIG. 4 may be used as thesecond set. The second set may be divided into non-overlapping subsetsin order to detect the appropriate quadrant. For example, using theeast-west rounded antennas of FIG. 3, one subset may cover the northeastand southeast quadrants, and the other subset may cover the northwestand southwest quadrants.

The shape of the antennas may be adjusted from the rectangular, roundedantennas of FIG. 3 or FIG. 4. For example, the antennas may be wedgeshaped or pie shaped. The intersection between sets may differ from theright-angle intersection shown in FIG. 7. For example, the intersectionbetween a wedge shaped antenna and a rectangular antenna is notnecessarily a right-angle intersection.

Antenna Arrangements for Gameplay

The intersecting, overlapping antennas (e.g., FIG. 7) may also be usedin situations where a single antenna would ordinarily suffice. Considera gaming table that has individual betting spots that are reserved forspecific types of bets. Each betting spot may be monitored using asingle, dedicated antenna. For example, a blackjack table has definedspots for betting a “split” or a “double down” when those bets areavailable according to the gameplay.

The array of intersecting, overlapping antennas (e.g., FIG. 7) may beused in place of the one or more antennas dedicated to monitoring theindividual betting spots. The array allows discrete stacks of bets to betracked. In addition, the array is more forgiving of sloppy tokenplacement, as the array itself may be larger than the individual bettingspots.

Layout Examples

FIG. 13 shows a stylized top view of a portion of the Baccarat table ofFIG. 1, with the addition of overlapping, intersecting antennas. Theantennas include a first set of east-west antennas 310 a, 310 b, 310 cand 310 d (cf. FIG. 3; collectively 310); a second set of east-westantennas 320 a, 320 b, 320 c, 320 d and 320 e (collectively 320); afirst set of north-south antennas 410 a, 410 b, 410 c, 410 d, 410 e, 410f, 410 g and 410 h (cf. FIG. 4; collectively 410); and a second set ofnorth-south antennas 420 a, 420 b, 420 c 420 d, 420 e, 420 f and 420 g(collectively 420). The antenna sets 310 and 320 are overlapping, andthe antenna sets 410 and 420 are overlapping. Due to the shapes of thebetting areas, the shapes of the antenna sets 310, 320, 410 and 420 arenot uniform, in contrast to the antennas 700 of FIG. 7; still, theantennas 310 and 320 may be described as being in one direction(east-west), and the antennas 410 and 420 may be described as being inanother direction (north-south). The east-west antenna sets 310 and 320intersect the north-south antenna sets 410 and 420. Note that theintersection between two antennas (e.g., 410 h and 320 a) may be anoffset intersection (e.g., offset from ninety degrees), instead of theright-angle intersection of FIG. 7.

For a full Baccarat table, the antenna arrangement of FIG. 13 may beduplicated for a total of six overlapping, intersecting antennaportions. Each of the antenna portions may be controlled by a system1000 (see FIG. 10), with the six circuits 1000 for the full Baccarattable connecting to a computer 1030.

FIG. 14 shows a stylized top view of the roulette table of FIG. 2, withthe addition of overlapping, intersecting antennas. The antennas includea first set of fourteen east-west antennas 310 a, 310 b, 310 c, 310 d,310 e, 310 f-310 m (not shown) and 310 n (collectively 310); a secondset of thirteen east-west antennas 320 a, 320 b, 320 c-3201 (not shown)and 320 m (collectively 320); a first set of north-south antennas 410 a,410 b, 410 c, 410 d and 410 e (collectively 410); and a second set ofnorth-south antennas 420 a, 420 b, 420 c and 420 d. The antenna sets 310and 320 are overlapping, and the antenna sets 410 and 420 areoverlapping. The east-west antenna sets 310 and 320 intersect thenorth-south antenna sets 410 and 420.

The antennas for the roulette table of FIG. 14 generally form a gridthat corresponds to the betting spots on the table. The antenna set 410corresponds to the center of each column, and the antenna set 420corresponds to the line between each column. The antenna set 310corresponds to the center of each row, and the antenna set 320corresponds to the line between each row. The intersection between setsenables the system to determine the location of all the bets on thetable. The antennas of FIG. 14 may be controlled by the system 1000 (seeFIG. 10), connecting to a computer 1030.

Antenna Sequencing Options

The system may implement a number of ways to sequence energizing theantennas. In general, it is undesirable to energize all the antennas atonce. It is undesirable to energize two adjacent antennas at once due tocross-talk. Cross-talk may also occur when energizing two adjacentantennas simultaneously. Similar cross-talk concerns may occur foroverlapping or intersecting antennas.

One way to sequence the antennas is to energize one at a time in astraight sequence. In this case, the controller 1010 (see FIG. 10)coordinates the subcontrollers 1020, 1022, 1024 and 1026 to operatesequentially. An example is the following sequence: 310 a (see FIG. 3),310 c, 320 a, 320 c, 310 e, 310 b, 310 d, 320 b, 320 d, 410 a (see FIG.4), 410 c, 420 a, 420 c, 410 b, 410 d, 420 b. Another example is thefollowing sequence: 310 a, 410 a, 310 c, 410 c, 320 a, 420 a, 320 c, 420c, 310 e, 310 b, 410 b, 310 d, 410 d, 320 b, 420 b, 320 d. Note that thestarting point is arbitrary.

Another way to sequence the antennas is to occasionally read two or morenon-adjacent and non-intersecting antennas at a time, to reduce the timeit takes to read the area. In this case, the controller 1010 coordinatesthe subcontrollers 1020, 1022, 1024 and 1026 to operate sequentially(similar to the previous examples), but also to perform simultaneousreads occasionally. An example is the following sequence where sometimestwo antennas are read at the same time: 310 a and 310 c, 310 b and 310d, 310 e, 320 a and 320 c, 320 b and 320 d, 410 a and 410 c, 410 b and410 d, 420 a and 420 c, 420 b. By doing up to two reads at a time, thenumber of steps required to read the area is reduced from sixteensequential reads to nine reads. Other patterns are possible to reducethe total read time.

In general, the system does not read two adjacent antennassimultaneously (because it would diminish the spatial resolution, e.g.,the ability to locate the bet). According to an alternate embodiment,the system implements a “fine” array that is then turned into a “coarse”array by energizing adjacent antennas simultaneously. The rationale fordoing so is to speed up the read cycle.

Another feature is to add a switch to each antenna. The switch maydisconnect the antenna from the control circuit (e.g., the system 1000in FIG. 10) and create a shorted loop. This prevents the antenna fromreceiving energy when another antenna is active, thereby reducingcross-talk. As an example, when one antenna is active, all otherantennas are disconnected. As another example, when one antenna isactive, all antennas with the same orientation are disconnected (e.g. inFIG. 3, when 310 a is active, all other antennas in 300 aredisconnected).

Read Time Options

In general, the read time for reading the entire array (e.g., the array700 of FIG. 7) is sufficient to detect sleight-of-hand activity, e.g.,10 complete reads of the array occur every second. For normal gameplay,it is generally sufficient to perform 2 complete reads of the arrayevery second. Note that—depending on the RFID protocol in use—the actualread time of each antenna may depend upon the token load (the number oftokens detected by the antenna). For example, the tokens will oftenimplement an anti-collision response protocol to prevent them all fromresponding at the same time when energized. As a result, the read timemay be decreased as the technology used to implement the tokens isadjusted to reduce the response time.

As discussed above, to speed up the read cycle for the entire array, thesystem may energize multiple antennas simultaneously. Energizingnon-adjacent antennas will not diminish the spatial resolution of thesystem. Energizing adjacent antennas will diminish the spatialresolution (e.g. from “fine” to “coarse”).

Matching Tokens to Bets

As mentioned above, the tokens have identifiers. In general, when atoken receives the excitation field generated by an antenna, the tokenresponds with its identifier. The computer (e.g., the computer 1030 inFIG. 10) may store a database that corresponds identifiers to tokenvalues. When the controller 1010 communicates a set of identifiers tothe computer, the computer may respond with the corresponding values.

Consider the following TABLE 4 as an example of the information in adatabase of token identifiers and token values:

TABLE 4 Identifier Value ID0000-ID0999  $1 ID1000-ID1100  $5ID1101-ID1200  $10 ID1201-ID1300  $25 ID1301-ID1400  $50 ID1401-ID1500$100

If a bettor places a bet of $85 in a stack of three tokens, the system1000 (see FIG. 10) detects the tokens (e.g., ID1301, ID1201 and ID1101)and sends the identifiers and the corresponding signal strengths to thecomputer 1030. The computer 1030 uses the signal strength information todetermine the location, and since the signal strength informationindicates that all three are at the same location, the computer 1030determines that the tokens are in a stack and thus a discrete bet. Thecomputer 1030 sends the three identifiers to the control computer 1040,which responds with the values ($50, $25 and $10). (If the controlcomputer 1040 does not recognize a particular identifier, the controlcomputer may respond with an error message.) The computer 1030 may thenuse the values to provide feedback to the dealers or players, forexample by displaying the values of bets ($85) on a video monitor.Similarly, the system detects other bets and displays all the values,which increases the accuracy of payouts. The value information may alsobe used for auditing purposes, for example to confirm that a particulargame is operating according to its expected house edge, to view theamount of action occurring at the table, to track that the appropriatehouse rake or time charge has been paid, etc.

As roulette tables use colored tokens specifically for roulette, not thestandard tokens used by the casino, the system architecture implementingthe chip database may be simplified. For example, the computer 1030 maystore a chip database that contains the identifiers of all the roulettetokens. The computer 1030 may connect to one or more roulette tables. Ifit is desired to extend the system, the computer 1040 may be added(e.g., for access to the overall chip database, for connecting theroulette table to a broader auditing system, etc.).

Enhancing Gameplay

Once the system knows the locations and amount of bets, this enablesvarious enhancements to the gameplay, for example to monitor and improvethe accuracy and timeliness of actions. In general, the gameplay occursin modes: bet placement mode, outcome mode, collection mode, payoutmode, and postgame mode.

Initially, the system is in bet placement mode, allowing new bets to beplaced and changed. At some defined point in time, bets can no longer bechanged. For example, in Baccarat, bets cannot be changed after thefirst card is dealt. In roulette, bets cannot be changed after the ball“drops”. In outcome mode, the outcome of the game is known and gameplayends. For example, in roulette the outcome mode is entered when the balllands on a number, and in Baccarat the outcome mode is entered wheneither the banker wins, the player wins, or a tie occurs. In systemsthat feature manual transitions, the dealer may indicate the entry ofoutcome mode, for example by using a touchscreen to touch the resultingnumber (in roulette) or touching buttons corresponding to banker win,player win or tie (in Baccarat). In systems that feature automatictransitions, the system may (in Baccarat) watch cards as they areremoved from the shoe, and may keep a count for the banker hand and theplayer hand, and thus can determine the result (banker win, player winor tie).

Once outcome mode has ended, the system enters collection mode. Incollection mode, the dealer collects the losing bets. It is possible toautomate the transition from outcome mode to collection mode. In thecases where the computer also knows (by independent means) the outcomeof the game (winning versus losing bets) and the odds associated witheach bet, the system may calculate the correct payouts and help toensure proper collection and disbursement. Furthermore, the systemcan—over a series of games—help ensure that the net (winners minuslosers) converge to the statistical norms. In the case where the systemknows the locations of the bets and the result of the gameplay, thesystem thus knows which bets lost and must be collected.

Once collection mode has ended, the system enters payout mode. In payoutmode, the dealer pays out the winning bets. The system knows thelocations of the winning bets to be paid out. The dealer may manuallyindicate the transition from collection mode to payout mode after thelosing bets have been collected, for example by using the touchscreen,or the system may transition automatically (e.g., by detecting that alllosing bets have been removed).

The system may have other modes, such as a postgame mode after payoutshave been made but before new bets are being accepted for the next game,etc. The transitions between modes can be manual or automatic dependingon the information available to the computer.

The system may verify the accuracy of the dealer's collections andpayouts at various points. When the system transitions from collectionmode to payout mode, the system may verify that all losing bets havebeen collected. In payout mode, players are allowed to remove theirwinnings at any time. For this reason, it is desirable to track eachwinning bet independently. To accomplish this, the system associateseach payout to its respective winning bet. Dealers are taught specific“rules” to systematize this process and make it easy for securitypersonnel to monitor activities. In particular, payouts are placedproximally to their respective bets. To exploit RFID tracking to itsmaximum potential, the system helps to monitor the location of eachpayout relative to its winning bet.

For example, it is desirable during payout mode to correctly associatespecific payouts with specific winning bets. The first step is toaccurately locate the bets in order to segregate winners from losers.Then, after odds are taken into account, the system is able to track inreal-time that payouts are individually tied to each winning bet.

As an example for Baccarat (see FIG. 1), the system knows the result(e.g., the banker wins), so the bets for the banker to win are to bepaid out and the bets for the player to win or the bets to tie are to bepicked up. The losing bets are located at the tie spots (140 a-140 b)and the player betting spots (120 a-120 l). Once the gameplay is over(resulting in the banker winning), the system transitions (manually orautomatically) to collection mode, and tracks the dealer as he collectsthe losing bets at 120 a-120 l and 140 a-140 b. The system thentransitions (manually or automatically) to payout mode, and the systemreads the spots 120 a-120 l and 140 a-140 b to verify that all losingbets have been collected The dealer then pays the winning bets at thebanker betting spots 130 a-130 l. (Bets on the banker pay 19 to 20.) Thesystem then transitions (manually or automatically) to postgame mode,and the system reads the spots 130 a-130 l to verify that each payout iscorrect. For example, if there are bets of $500 and $1000 at 130 a(which the system has detected earlier), the dealer pays out $475 and$950. The system then reads spot 130 a and the result is four bets of$500, $475, $1000 and $950; the system is aware of the 19-to-20 payoutrule and thus is able to verify that these are the correct amounts. Thesystem also detects that the $475 payout is proximate to the $500 betand that the $950 payout is proximate to the $1000 bet.

As an example for roulette (see FIG. 2), the system knows the winningnumber (e.g., “1”) and, being programmed with the rules of the game, maydetermine the ancillary winning bets such as red/black, street, etc. Thelosing bets are located at the spots that do not include “1”, such asthe other numbered spots, the “black” bet, the “even” bet, the streetsthat do not include “1”, etc. Once the gameplay is over (resulting inthe “1” number), the system transitions to collection mode, and thedealer collects the losing bets at the losing locations. The system thentransitions to payout mode and verifies that no tokens are detected atthe losing locations (and thus have all been collected). The dealer thenpays the winning bets: straight bets (bets within the spot 220 a), splitbets (bets on the lines between the spot 220 a and adjacent spots forthe numbers “2” and “4”), street bets (bets on the line between the spot220 a and the “1st 12” area), corner bets (bets on the corner of thespot 220 a and the numbers “2”, “4” and “5”), etc. The system thentransitions to postgame mode and reads the array to verify that thepayouts are correct in the winning areas. For example, if there are betsof $1 and $5 as straight bets in the spot 220 a and a bet of $5 on “red”(which the system has detected earlier), the dealer pays out $35, $175and $5. The system then reads the array and detects six stacks of $1,$35, $5, $175, $5 and $5; the system is aware of the payout rules andthus is able to verify that these are the correct amounts, and that eachpayout is located proximate to its corresponding winning bet (exploitingthe ability to locate the payouts relative to the location of theoriginal winning bets).

Additional Embodiments

FIG. 15 is a diagram showing a system 1500 and antenna array 1550 wherethe antennas are overlapping and oriented in a single direction. Thesystem 1500 is similar to the system 1000 (see FIG. 10, with similarreference numerals) but having only two subcontrollers 1020 and 1022.The antenna array 1550 is similar to the array 300 (see FIG. 3, withsimilar reference numbers).

The operation of the system 1500 and antenna array 1550 is generallysimilar to the system 1000 and array 300 (or the method 1100 of FIG. 11)as described above, with the system 1500 implementing interpolation (asdescribed above) to determine the location of a RFID gaming token. Morespecifically, the controller 1010 controls the subcontroller 1020 toselectively energize the subset 310, and controls the subcontroller 1022to selectively energize the subset 320 (see FIG. 3). The controller 1010receives (via the subcontroller 1020) a first signal strength resultingfrom reading the RFID gaming token in the betting area according to thefirst subset being selectively energized, and receives (via thesubcontroller 1022) a second signal strength resulting from reading theRFID gaming token in the betting area according to the second subsetbeing selectively energized. The system 1500 determines the location ofthe RFID gaming token in the betting area by interpolating between thefirst signal strength and the second signal strength. The controller1010 may perform the interpolation, or the computer 1030 may perform theinterpolation.

FIG. 16 is a diagram showing a system 1600 and antenna array 1650 wherethe antennas in one direction are overlapping, and the antennas inanother direction are not overlapping. The system 1600 is similar to thesystem 1000 (see FIG. 10, with similar reference numerals) but havingonly three subcontrollers 1020, 1022 and 1024. The antenna array 1650 issimilar to the array 700 (see FIG. 7, with similar reference numbers)without the overlapping subset 420 (see FIG. 4).

The operation of the system 1600 and antenna array 1650 is generallysimilar to the system 1000 and array 700 (or the method 1100 of FIG. 11)as described above, with the location determination being more precisein the y-axis direction than it is in the x-axis direction, due to theoverlapping antennas 300 in the y-axis direction. More specifically, thecontroller 1010 controls the subcontroller 1020 to selectively energizethe subset 310, controls the subcontroller 1022 to selectively energizethe subset 320 (see FIG. 3), and controls the subcontroller 1024 toselectively energize the subset 410 (see FIG. 4). The controller 1010receives (via the subcontrollers 1020 and 1022) a first plurality ofsignal strengths resulting from reading the RFID gaming token in thebetting area according to the first set being selectively energized, andreceives (via the subcontroller 1024) a second plurality of signalstrengths resulting from reading the RFID gaming token in the bettingarea according to the second set being selectively energized. The system1600 determines the location of the RFID gaming token in the bettingarea by comparing the first plurality of signal strengths and the secondplurality of signal strengths, in a manner similar to that describedabove.

The above description illustrates various embodiments of the presentinvention along with examples of how aspects of the present inventionmay be implemented. The above examples and embodiments should not bedeemed to be the only embodiments, and are presented to illustrate theflexibility and advantages of the present invention as defined by thefollowing claims. Based on the above disclosure and the followingclaims, other arrangements, embodiments, implementations and equivalentswill be evident to those skilled in the art and may be employed withoutdeparting from the spirit and scope of the invention as defined by theclaims.

What is claimed is:
 1. A system for locating gaming tokens on a gamingtable, comprising: a first set of antennas oriented in a firstdirection, wherein the first set of antennas defines a betting area ofthe gaming table, and wherein the first set includes a first subset ofantennas and a second subset of antennas, wherein the first subset andthe second subset are overlapping; a second set of antennas oriented ina second direction that differs from the first direction, wherein thefirst set and the second set are overlapping, wherein the second setincludes a third subset of antennas and a fourth subset of antennas,wherein the third subset and the fourth subset are overlapping; and acontrol circuit, coupled to the first and second sets, that isconfigured to selectively energize the first and second sets, that isconfigured to receive a first plurality of signal strengths resultingfrom reading a radio frequency identification (RFID) gaming token in thebetting area according to the first set being selectively energized,that is configured to receive a second plurality of signal strengthsresulting from reading the RFID gaming token in the betting areaaccording to the second set being selectively energized, and that isconfigured to determine a location of the RFID gaming token in thebetting area by comparing the first plurality of signal strengths andthe second plurality of signal strengths.
 2. The system of claim 1,wherein the first plurality of signal strengths includes at least onezero signal strength indicating that a corresponding antenna of thefirst set failed to read the RFID gaming token.
 3. The system of claim1, wherein the control circuit is configured to determine the locationof the RFID gaming token in the betting area by being configured todetermine a first antenna as being a closest antenna from the first setfor reading the RFID gaming token in the betting area according to ahighest signal strength from the first plurality of signal strengths, bybeing configured to determine a second antenna as being the closestantenna from the second set for reading the RFID gaming token in thebetting area according to the highest signal strength from the secondplurality of signal strengths, and by being configured to determine thelocation of the RFID gaming token in the betting area according to anintersection of the first antenna and the second antenna.
 4. The systemof claim 1, wherein the RFID gaming token is one of a plurality of RFIDgaming tokens, and wherein the control circuit is configured todetermine a location of each of the plurality of RFID gaming tokens inthe betting area by comparing, for each of the plurality of RFID gamingtokens, the first plurality of signal strengths and the second pluralityof signal strengths.
 5. The system of claim 1, wherein the RFID gamingtoken is one of a plurality of RFID gaming tokens, and wherein thecontrol circuit is configured to determine a plurality of locations forthe plurality of RFID gaming tokens in the betting area by comparing,for each of the plurality of RFID gaming tokens, the first plurality ofsignal strengths and the second plurality of signal strengths.
 6. Thesystem of claim 1, wherein the RFID gaming token is one of a pluralityof RFID gaming tokens in a stack, and wherein the control circuit isconfigured to determine a location of the stack in the betting area bycomparing, for each of the plurality of RFID gaming tokens, the firstplurality of signal strengths and the second plurality of signalstrengths.
 7. The system of claim 1, wherein the RFID gaming token isone of a plurality of RFID gaming tokens in a plurality of stacks, andwherein the control circuit is configured to determine a location ofeach of the plurality of stacks in the betting area by comparing, foreach of the plurality of RFID gaming tokens, the first plurality ofsignal strengths and the second plurality of signal strengths.
 8. Thesystem of claim 1, wherein the RFID gaming token is one of a pluralityof RFID gaming tokens in a plurality of stacks, and wherein the controlcircuit is configured to determine a plurality of locations of theplurality of stacks in the betting area by comparing, for each of theplurality of RFID gaming tokens, the first plurality of signal strengthsand the second plurality of signal strengths.
 9. The system of claim 1,wherein the betting area comprises a first betting area, wherein theRFID gaming token comprises a first RFID gaming token, furthercomprising: a third set of overlapping antennas, coupled to the controlcircuit, wherein the third set defines a second betting area adjacent tothe first betting area, wherein the control circuit is configured todetermine a location of a second RFID gaming token in the second bettingarea, wherein the control circuit is configured to fail to read thefirst RFID gaming token in the second betting area, and wherein thecontrol circuit is configured to fail to read the second RFID gamingtoken in the first betting area.
 10. The system of claim 1, wherein thecontrol circuit is configured to determine the location of the RFIDgaming token in the betting area by interpolating among the firstplurality of signal strengths and interpolating among the secondplurality of signal strengths.
 11. The system of claim 1, wherein thecontrol circuit is configured to selectively energize the first set in asequential manner.
 12. The system of claim 1, wherein the controlcircuit is configured to selectively energize more than one of the firstand second sets at a given time.
 13. The system of claim 1, wherein thefirst subset and the second subset are overlapping such that the firstset collectively has no dead spot.
 14. The system of claim 1, whereinthe first plurality of signal strengths corresponds to a signal strengththat is above a threshold and at least one signal strength that is belowthe threshold.
 15. A method of locating gaming tokens on a gaming table,comprising: providing a first set of antennas oriented in a firstdirection, wherein the first set of antennas defines a betting area ofthe gaming table, and wherein the first set includes a first subset ofantennas and a second subset of antennas, wherein the first subset andthe second subset are overlapping; providing a second set of antennasoriented in a second direction that differs from the first direction,wherein the first set and the second set are overlapping, wherein thesecond set includes a third subset of antennas and a fourth subset ofantennas, wherein the third subset and the fourth subset areoverlapping; selectively energizing the first and second sets; receivinga first plurality of signal strengths resulting from reading a radiofrequency identification (RFID) gaming token in the betting areaaccording to the first set being selectively energized; receiving asecond plurality of signal strengths resulting from reading the RFIDgaming token in the betting area according to the second set beingselectively energized; and determining a location of the RFID gamingtoken in the betting area by comparing the first plurality of signalstrengths and the second plurality of signal strengths.
 16. A system forlocating gaming tokens on a gaming table, comprising: a first set ofantennas oriented in a first direction, wherein the first set ofantennas defines a betting area of the gaming table, and wherein thefirst set includes a first subset of antennas and a second subset ofantennas, wherein the first subset and the second subset areoverlapping; and a control circuit, coupled to the first set, that isconfigured to selectively energize the first and second subsets, that isconfigured to receive a first signal strength resulting from reading aradio frequency identification (RFID) gaming token in the betting areaaccording to the first subset being selectively energized, that isconfigured to receive a second signal strength resulting from readingthe RFID gaming token in the betting area according to the second subsetbeing selectively energized, and that is configured to determine alocation of the RFID gaming token in the betting area by interpolatingbetween the first signal strength and the second signal strength.
 17. Amethod of locating gaming tokens on a gaming table, comprising:providing a first set of antennas oriented in a first direction, whereinthe first set of antennas defines a betting area of the gaming table,and wherein the first set includes a first subset of antennas and asecond subset of antennas, wherein the first subset and the secondsubset are overlapping; selectively energizing the first and secondsubsets; receiving a first signal strength resulting from reading aradio frequency identification (RFID) gaming token in the betting areaaccording to the first subset being selectively energized; receiving asecond signal strength resulting from reading the RFID gaming token inthe betting area according to the second subset being selectivelyenergized; and determining a location of the RFID gaming token in thebetting area by interpolating between the first signal strength and thesecond signal strength.
 18. A system for locating gaming tokens on agaming table, comprising: a first set of antennas oriented in a firstdirection, wherein the first set of antennas defines a betting area ofthe gaming table, and wherein the first set includes a first subset ofantennas and a second subset of antennas, wherein the first subset andthe second subset are overlapping; a second set of antennas oriented ina second direction that differs from the first direction, wherein thefirst set and the second set are overlapping; and a control circuit,coupled to the first and second sets, that is configured to selectivelyenergize the first and second sets, that is configured to receive afirst plurality of signal strengths resulting from reading a radiofrequency identification (RFID) gaming token in the betting areaaccording to the first set being selectively energized, that isconfigured to receive a second plurality of signal strengths resultingfrom reading the RFID gaming token in the betting area according to thesecond set being selectively energized, and that is configured todetermine a location of the RFID gaming token in the betting area bycomparing the first plurality of signal strengths and the secondplurality of signal strengths.
 19. A method of locating gaming tokens ona gaming table, comprising: providing a first set of antennas orientedin a first direction, wherein the first set of antennas defines abetting area of the gaming table, and wherein the first set includes afirst subset of antennas and a second subset of antennas, wherein thefirst subset and the second subset are overlapping; providing a secondset of antennas oriented in a second direction that differs from thefirst direction, wherein the first set and the second set areoverlapping; selectively energizing the first and second sets; receivinga first plurality of signal strengths resulting from reading a radiofrequency identification (RFID) gaming token in the betting areaaccording to the first set being selectively energized; receiving asecond plurality of signal strengths resulting from reading the RFIDgaming token in the betting area according to the second set beingselectively energized; and determining a location of the RFID gamingtoken in the betting area by comparing the first plurality of signalstrengths and the second plurality of signal strengths.